Technical aspects of status and expected future trends for wind power in Denmark

Abstract

The power system of Denmark is characterized by significant incorporation of wind power. Presently, more than 20% of the annual electricity consumption is covered by electricity‐producing wind turbines. The largest increase in grid‐incorporated wind power is expected to come from large (offshore) wind farms operating as large wind power plants with ride‐through solutions, connected to the high‐voltage transmission system and providing ancillary services to the system. In Denmark there are presently two offshore wind farms connected to the transmission system: Horns Rev A (160MW rated power in the western part of the country) and Nysted (165MW rated power at Rødsand in Eastern Denmark). The construction of two more offshore wind farms, totalling 400MW by the years 2008–2010, has been announced. This article presents the status, perspectives and technical challenges for wind power in the power system from the point of view of Energinet.dk, Transmission System Operator of Denmark. Copyright © 2006 John Wiley &Sons, Ltd

Wind power in modern power systems

“…Large offshore wind farms may inject significant power fluctuations into power systems [9], and such power fluctuations may affect neighbouring power systems, if it is not appropriately dealt with. For example, the offshore wind farm Horns Rev A in Western Denmark produces more intense active power fluctuations than the aggregated wind power produced by land based wind farms in the western Danish power system and shows frequent active power fluctuations within periods of tens of minutes, the power gradients reach 15 MW per minute, thus the 160 MW wind farm have the output power change between zero and the rated power in 10-15 min [10]. The system power balance could also be worsen by the deviations from the planned power exchanges between Norway and Sweden.…”

“…An area grid controller can perform the secondary control with the central power plants and tie lines to other neighbouring power systems, including the HVDC connections [10]. The area grid controller can cooperate with wind power dispatch centre for overall system power dispatch and control to deal with the wind power fluctuations.…”

A General Probabilistic Forecasting Framework for Offshore Wind Power Fluctuations

“…As a first step towards this understanding, Akhmatov et al [7] reported that at a temporal resolution of 10 min, certain weather conditions at Horns Rev and in particular north-westerly winds very much favored large wind power fluctuations. Then, Sørensen et al [8] proposed an aggregated model of individual wind turbines and showed its relative ability to simulate consistent wind power fluctuations at different time scales, from a few minutes up to 2 h ahead.…”

Geographic aggregation and wind power output variance in Denmark

“…Authors such as Parsons et al [23] focus on the demands exerted by wind turbines on external ancillary service providers and Gjengedal [24] argues that it may not be optimal to equip wind turbines with the techniques required to supply ancillary services. However, as Akhmatov et al [25] notes, progressively stricter grid codes tend to have improved wind turbines and therefore, they should be able to supply ancillary services in the future through the use of power converter coupling to the grid. Ride-though capability has been one of the focus areas of the increasingly stricter grid codes adding to short-circuit power.…”